GLEN KERTZ, FOUNDER of Valcent Products in El Paso, Texas, is looking for a few good algologists.

His company specializes in the mass production of algae, developing new technologies to turn bright green "pond scum" into a cost-effective, nonpolluting, energy-efficient alternative to fossil fuel. One of the few places where Kertz can find skilled workers is on university campuses — and even then, it can be difficult to lure an algologist (a research scientist well-versed in algae) to a private-sector job.

"The pool you have to select from is relatively shallow," he says. "You have to find someone who is willing to pack up and quit whatever projects they're working on." It's a particularly hard sell when the scientist is tenured. Even a start-up company in a hot industry like renewable energy has "uncertainties and risks, whereas, if you have tenure, you're set for life," he says.

Kertz's tale illustrates the unique hiring challenges often faced by start-ups in the burgeoning green sector. While consumer demand is growing for eco-friendly products and services, snagging a work force that's educated, experienced and well-qualified in everything from wind-turbine design to organic landscaping can be a difficult task.

Sometimes, it's the "experience" part that's lacking — and that doesn't necessarily mean experience in the environmental field. In Los Angeles, Gregg Steiner, founder of Green Life Guru, a company that advises homes and businesses on how to go green, says he can find plenty of young people right out of college to join his team. He recruits heavily from University of Southern California and University of California at Los Angeles, both of which have strong environmental-studies programs.

But while young people are "pretty much the most passionate people about the environment," he says, they sometimes lack the customer-service training and wisdom of more seasoned employees. Steiner's workers spend entire days conducting energy audits in people's homes and need to be able to work independently while interacting with homeowners. Ideally, he'd like to hire baby boomers "with a lifetime of work experience" who want new green careers. But "I'm having trouble finding [them]," he says. "I'm not sure how to target those people."

Of course, in many ways, some of the challenges that green companies face in hiring the best candidates for the job are no different than what any other business deals with, says Kevin Doyle, president of Boston consulting firm Green Economy and author of The ECO Guide to Careers That Make a Difference.

"There's really no meaningful category called 'green' workers," he points out. Certainly, a growing number of businesses — everything from organic restaurants to eco-friendly dry cleaners — might require employees with special knowledge or training in environmental areas. But for the most part, the "green" part is just an added part of the title, he says. For instance, a developer who wants to construct green buildings still needs to find engineers; the only difference is now that engineer might need to be certified in the U.S. Green Building Council's LEED (Leadership in Energy and Environmental Design) or Energy Star guidelines.

Doyle recommends that companies turn to their industry or trade groups for tips on where to find workers with special environmental skills. "The professional associations have been on this for a while, and have understood what 'going green' means in that particular field," he says.

Professional associations and other nonprofits often provide training or certification, which can be useful for bulking up an existing or potential employee's skills. Solar Energy International, for example, offers workshops and online courses in solar, wind and water power. The American Management Association has launched a three-day seminar called "Implementing Sustainability Strategies," designed to teach participants how to translate green business practices into economic results. The National Organic Program offers certification for producers or handlers of organic foods.

Educational institutions — everything from major universities to tiny community colleges — offer training for all levels of students, and can be good places to recruit from or send employees to for more schooling. Massachusetts Institute of Technology's Sloan School of Management has created a popular Laboratory for Sustainable Business that teaches students (the majority of whom are MBAs) various aspects of sustainability as it relates to the business world. Hocking College, a two-year technical college in Nelsonville, Ohio, recently won a $1.6 million grant from the U.S. Department of Commerce to build an advanced energy institute, slated to open in the fall of 2009.

Some companies are choosing to train their own workers, too. RWA Resource Recovery in New York, a for-profit microbusiness that's run by the nonprofit Doe Fund, collects waste cooking oil from restaurants and sells it to energy producers, which convert it into biodiesel fuel. "It's a skilled job, but a dirty job — it can be tricky finding people to do that," says Joanna West, director of business development at Doe Fund. "So we train our own people." Doe Fund has long specialized in training, helping the formerly homeless and incarcerated improve their job skills. Now, RWA Resource Recovery is training workers to handle the nontoxic oil and use vacuum trucks for pick-ups. An added bonus is that employees — particularly those who have had a few hard knocks in life — are enjoying learning eco-friendly work skills. "People want to feel like they're part of something important, and something big, and something that gives back," West says.